Prepare the vegetables. Wash and chop the cabbage into bite-sized pieces. Dice the onion and mince the garlic. Keep the cabbage pieces reasonably uniform so they cook evenly.

Brown the beef. Place a large soup pot over medium-high heat. Add the ground beef and cook for 6–8 minutes, breaking it into small crumbles with a wooden spoon. Continue until the meat is browned and no longer pink.

Drain excess fat if necessary. If using fattier beef, carefully drain off excess grease, leaving a small amount for flavor. If using lean beef, add the olive oil only if the pot appears too dry.

Cook the aromatics. Reduce the heat to medium. Add the diced onion and cook for 3–4 minutes until softened and slightly translucent. Stir in the garlic and cook for another 30–60 seconds until fragrant.

Add the seasonings. Mix in the paprika, Italian seasoning, black pepper, salt, and optional red pepper flakes. Stir for about 30 seconds to release their aroma without burning the garlic.

Build the broth. Add the tomato paste and stir for 1 minute. Pour in the diced tomatoes and beef broth, scraping the bottom of the pot to loosen any browned bits. Bring the mixture to a gentle boil over medium-high heat.

Add the cabbage. Stir in the chopped cabbage. Once the soup returns to a gentle boil, reduce the heat to medium-low and cover the pot partially.

Simmer until tender. Cook for 20–25 minutes, stirring occasionally. The cabbage should be tender but not completely mushy, and the broth should have a rich, savory color. Ensure the ground beef is fully cooked.

Adjust the flavor. Taste the soup and adjust the salt and pepper as needed. Add the optional lemon juice for brightness. If you prefer a thicker broth, simmer uncovered for another 3–5 minutes.

Garnish and serve. Ladle the hot soup into bowls and sprinkle with chopped parsley. Serve on its own or alongside a low-carb side dish for a hearty meal.